This proposal investigates the contributions of cognitive and physiological factors in the behaviors of cigarette smokers and overweight individuals. The proposed research on cigarette smoking and that of obesity have been combined in the grant application because the same general theoretical framework and methodolgy guide the research strategy. An understanding of the behaviors of smokers initially arose out of the obesity studies. Light smokers appeared to respond to external cues, as do the obese. Heavy smokers appeared to be more affected by physiological changes, as is the case with individuals of normal weight. The experiments of smoking would determine the extent to which smoking affects emotional reactions, as well as one's ability to perform cognitive tasks. It would examine the role of physiological arousal in governing the occurrence of the smoking act. It would also investigate a possible procedure to help smokers break their habit. The obesity research would document the relative insensitivity of overweight individuals to physiological changes. The studies would assess the association between body weight and cognitive abilities such as creativity, visual and auditory imagery, and the capacity to choose among alternatives. Finally it offers an explanation of why people have a difficult time attempting to lose weight by dieting, it suggests a method of predicting which individuals would have the most difficulty, and it proposes one technique for weight reduction.